How to set up Algebraic Equations to Match Real World Problems!

How to convert words to equations… Problem.  Helen has 2 inches of hair cut off each time she goes to the hair salon. If h equals the length of hair before she cuts it and c equals the length of hair after she cuts it, which equation would you use to find the length of Helen's hair after she visit the hair salon? B a. h = 2 − c      c. c = h − 2 b. c = 2 − h      d. h = c − 2

How to convert words to equations… Problem.  Helen has 2 inches of hair cut off each time she goes to the hair salon. If h equals the length of hair before she cuts it and c equals the length of hair after she cuts it, which equation would you use to find the length of Helen's hair after she visit the hair salon? B E 1. Rewrite the question in words 2. Set it equal to… 3. The rest of the boxed-in words length of Helen’s hair after cut = length of hair before cut – cut off hair

How to convert words to equations… Problem.  Helen has 2 inches of hair cut off each time she goes to the hair salon. If h equals the length of hair before she cuts it and c equals the length of hair after she cuts it, which equation would you use to find the length of Helen's hair after she visit the hair salon? B E length of Helen’s hair after cut = S length of hair before cut – cut off hair substitute the c, h, and 2 into the relationships above, and then match with the equations (a) through (d). C = h - 2 a. h = 2 − c      c. c = h − 2 b. c = 2 − h      d. h = c − 2

How did we know to subtract?? C = h - 2

Notes Problem: Jeanne has $17 in her piggy bank. How much money does she need to buy a game that costs $68? Hint: Let the variable represent what you are looking for… IOW: What you underline in the CUBES method! Solution: Let x represent the amount of money Jeanne needs. Then the following equation can represent this problem: Variable Algebraic Expression 17 + x = 68 We can subtract 17 from both sides of the equation to find the value of x. 68 – 17 = x 51 = x

Example 1:

Example 2:

Example 3: